Detected signal direction finder



Nov. 16, 1943. H. G. BUSiGNlES 2,334,247 I DETECTED SIGNAL DIRECTION FINDER Filed March 6, 1941 FIG.1. 2

Patented Nev. is, 1943 Henri G. Busi'g'nies, F-orest Hills, N. Y., assignohte International Standard Electric Corporation;

' Tnis'invention relates to direction finding systents and more particularly to direction finders using cathode ray"indicators.

tube 'indicatorsin which the signal is usedfto caus l-anal deviation offthe cathode ray'beam so that a patternistraced on the screen fof'the tube. It has also been proposed to apply the carrier together with the modulating signal so that the "pattern is "outlined in a screen which is normally bright. However, in these latter types of indicators the beam isjonly on the screen part of the timethe" remaining portion of the time the beam is defieicted'to the sides of the tube oh the screen. Thus; considerable cathode ray power is wasted and thescreen'is not lighted to thegreatesti'possible brillance. [In accordance 'withmy invention the advantage of havingafully'illuminated screen without achieved.

,tecting theenvelope signal before applying itto thefcathode' ray :tube indicator to produce the radial v dflection. In the preferred forinth low-A nals areformed so. thatthe normal minimum or of thecathode raybeam. fWhen such a receiver is used, theinterruptions caused by keying at the transmitter produce lines of light which may ob sears the directional indication.

. -'It" i's' afu'rther object of iny inverition'to prop was an arrangementwhich will permit selective V indication by .a solid attern system or by outline ssme'pattemtn1y to r'erider'the' system u'r'iiversally applicable regardlessof the natiireof the signal. p l

Abetter. understanding of my invention and the obje'cts'aiid ieaturestnereor will be had from the fparticular descriptionthreof made with referenceto-the accompanying drawing, in which 1 is a diagrammatic illustration of a circuit incorporating my invention, and

Figs. 2, 3 and 4 are diagrams of cathode ray screens illustrating the operation in accordance with my invention.

In Fig. 1, I and 2 indicate right angularly arranged directional antennae which may be loops in; cathode ray lindicators used with caress-011' finders, it ha's be'e'n proposed to use cathode'ray the disadvantage of waste cathode ray is This ma be most simply accomplished was ticiilarly the casewh'en inverted modulation sig zerqfsi'gnai level produces the greatest deviation screen, However,i" such acasfti eimage New York, N. Y.-, a corporation of Delaware v Application Mar-cu t, 1941 Serial ammo 4 01mm. (o1. 250-11).

as snownbr other desired antenna term; Theputput of these loop antennae feed into a gohidiht'i s from wrlien nenveitpe f equency dependentju'pon the rate "of rota ion or thjgb'hi dni'et'er'jis applied to receiver t, catneae r ay indicating tube as provided mm deflection mates :1, accelerating electrode 12, een htraung elem troaeyla and emitting 'eathode M, is utilized. A two+phase generatore is 'op'eratedin'tl'zhed re tionshipw'ith'the gsmometerby a at norniallyi'o'tate the cathcaezray intinied' without detection to "the accelerating:e16ti6t1,-

trien a pattern or the form shown rig. 2' wouili be. obtained. 'It can be seen tnatiafrge per: centage of the carrier nveiepe wtuiatnen oc'iir outside the surface of catnpue s reen 2D. "This energy "represents losses arra tends-tdi auee the brilliance or the iilumination cf thecathode screen. Ofc'ouise, the ai'ridu'ntdf deflection could be reduced so" that the entire pattern reproduced within the limits.

the .d'ii-ec'tivepat'tern would be greatlyreducediana would oily siist wte'areiat veiy'smart spot near the tamer 6f the catnqderaysreen. QInjfFig. "sisrshotvn the envldteffiattern tracing on the cathode ray screen 2 when meuppehair of the detected waveisiisditoproduce the nin cation. In this "arraiignier'itth iridicatirig'por trainer the screen relatively" small ghouls-mt flatworms illuminated parties of ttnssren is not re uce as rt'weuId-te were the entire patternwithout'dtectiofi tolobtaii i'thepattern'olotai from detector 5 iii'ay'b' enir'i'idye ire'ctly to pro; dude the defictionby cdriiiection oaccelerating electrode fig as win be near, The output orue': tector' is may comprise, the upper or lower half of the received carrier as modulated in accordance with the effective orientation of antenna I, 2. By applying this output to electrode l2 with appropriate polarity, electrons in the cathode ray may be acceleratedwith various dere uced. In order s grees less than normal, thus rendering them more susceptible of radial deflection when they encounter the sweep circuit field supplied by Kenthe minima defining a generally vertical axis in the sense of Fig. 3 may be employed for direction indication.

In Fig; 4 the preferred type ofpattern obtained I: on the cathode ray screen is illustrated." In this.

arrangementthe entire diameter of" the screen Under these circumstances, the pattern 2,334,247 f v v the unfiltered output or thetively. for applying filtered output to one of the grids'oi a double element valve 23. The anodes or the. valve I! are connected together inparallel and are so arranged that the output, from valve 23 is applied to accelerating electrode II. By using thereaistance elements 2|, 22, the eflectlveneas ,ot the pattern containing the carrier ripple or the Illmay be used for direction indication since 'onlythe lower half of the envelope-is producedat. the output of the detector.

energy of the cathode ray may be usefully em ployed toproduce illumination on the screenand.

yet a relativ'ely; large, easily .read indication '15 Consequently all the oI .-p otentiometers ii and. vIt'ah'ould also be understood that the output from tube '28 may,

Y if'desired; be applied to the deflecting electrodes 'of tube 10' to causethe radial deviation instead obtained. As in the case of Fig.3, output'ot detecto'r 5l-may be. applied directlyv to accelerating electrode i2. 1 However, the polarity of such energy as so (applied is op o it to that em oy to produce .thepattern of Fig. 3. Thus, as-the; varying accelerating potential is applied, cathode ray electronsTrnaybe'accelerated with various degrees greater than normal, thus rendering them lessgsusceptible of radial deflection when they encounter the sweepic'ircuit field, as will be clear.

'It should be understood that the principles outlined above apply equally well to systems wh'ereinthe radial deviation is obtained by applyirig the: detected output, together with the carrier frequency component to the deflectin plat of the cathode ray tube through suitable distributing means, ;instead oi utilizing the accelerating elec f trdeior "the purpose of producing the radial deviat'ion ofthe beam. Moreover, the receiver trode, ii. In the. output or commutator} are may be ofa type such'that'an inverted wavelon an intermediate carrier is produced at the output.

the am level and; easily read directional indicatioris aregthereforaobtained. v

i lti'should fb'e understood" that the mean i r,

obtaining efiective rotation of. the a tenna may be an electronic g'oniometer system or an actual able directive antenna without altering the iieipi s' oith'isZinvention as described. f

I When. nverted modulation signals are used a 'singleline outlining the patternon the cathode ray screen be used instead of the solid illumina coupled to said antenna, acathode ray indicator, rneansforj causinga radial oi the cathode "ray" beam of said indicator-,1;

- tered envelope frequency; nee 01? time!!! be electrode selectively applied to the acceleratingl2 so that either oi'these patterns may selectively be reproduced. 'It-is clear that both that is, the carrierecharacterized orient the plain "envelopeiree of carrier ripple, may be reproduced 1 "simultaneously if desired,in'which case one'ot the. patterns maybe-made more brilliant than the other according to the'relative' adjustment ofj being applied to the accelerating g 'Itshould' be I distinctly understood that, 1 above. described circuit illustrates onlyfa terred embodiment ofmy'inventionsandm not indicate thescope of my invention. may

alterations and variations of the system within in the artj I a what is claimedis: r 1 1. A direction, finding 'systeml including an e!- iectiveiy' rotatable receiving antennapa receiver the scope of my invention will occur to one t in th'ejoutput or "said receiver for: producing" a d t d n l pe pattern or energz derived from said antenna, saiddetector type tionfprfo'duced whenthe carrieris also applied. 1

is. particularly trueif the ,signals are being" .rrom a'transmitterfin which the'energy ,ifsI-keyed; In 'or'der.'to ,take ,care' or this matter :1

recei provide in Fig; '1; q a il'owflp ass nitem connected i gtnemitput or; detector i kjlllilter sis preferably designed so as to .passireguen'cies in theneigh-jliQlhOOd of the gonioineter eiie'ctive rotation ire; j

quency, and ,to exclude the carrier ,ir'equen'cy.

may be alternately applied to accelerating elecprovided resistance, elements "Z'I 'and ,respec cathode ray beamior: said indicator; a detector inthe output of. said {receivenior qete tedenve ipatt qrenems mm.

. t v .vsa. Acofiimutator s isp'rovided so that the Zuniiltered output Ironii detect'or'i l5 and the]. filtered wave es ed w ve e velope f 4.. ,direction which, produces at. the io'utputthereo'tf only one "dfjithe. upperand lower haivjes o! the received carrier. wave and means for de-j. tected 'envelop'ef together with' Ire quency to said means for causing radial displacement of said beam comprises an trode in the path ,of the cathode 3 3.;A direction flnderi according toclaim 1,:

wherein lsaid -detectoi' isoi the at its output'only "the lowerl l'fionni the du w I I I v 1 produeeigtnei indication, is often desirable that ding means IQ! "causlngfa radial "displacement oi the said antenna,'a,low pass'fllt'ei'j means in the output f e t t de 'i e he low. ummus 1 t lope. d me ns 1 r=- .ele v lvlamlms" desiredproportions of saidcomplete'detectad, i

or said low trequencyenveiope to said eausingmaiai displacement or said duce'; the desired pattern on said cathode ray S reenf i c znosronmap syfltieliiiifichw a d-'1 'iectlvely rotatable receiving antenna, a, coupled to saidantenna,"acathoderaylndicabr- 

